docs: def run(self, incremental=None, run_id=None):
          """Queue the execution of a particular crawler."""
          state = {
              'crawler': self.name,
              'run_id': run_id,
              'incremental': settings.INCREMENTAL
          }
          if incremental is not None:
              state['incremental'] = incremental
  
          # Cancel previous runs:
          self.cancel()
          # Flush out previous events:
          Event.delete(self)
          Queue.queue(self.init_stage, state, {})